The leader of the independent bus drivers union in Tehran, Iran, was released on bond from Iranian prisons.
The four charged that they had been arrested for participating in demonstrations calling for political reform, ending corruption and providing services to the people.
Amnesty International and the International Confederation of Chemical, Energy, Mine and General Workers Unions have assailed recent arrests of trade unionists and other Iraqi activists.
President Evo Morales' socialist government is close to warding off a challenge to its staying power.
Those in the ruling circles intend to complete the transformation of the country into a totalitarian state.
International trade union leaders are calling for decisive and ambitious climate action centered on social protections, doubling the number of green and decent jobs and ensuring a just transition to a greener future.
Two sets of realities are opposed: a small, wealthy, U.S.-backed minority and popular mobilization, always in the background, but now gathering new strength.
The two right-wing parties in the Mexican congress have come together to promote a labor law "reform" that unions see as an effort to crush organized labor.
On the streets of London on Saturday three-quarters of a million people staged the biggest protest yet in the fightback against the Tory-led coalition's brutal cuts program.
Egypt has cut its forecast for growth by almost half and has estimated that the unrest cost the nation about $1.7 billion, largely stemming from tourism losses.